Plow



5 Sheets-Sheet l H. E. PRUSS PLOW Filed NOV. 2, 1936 Dec. 6, 1938.

INVENTOR.

ATTORNEY.

Hugo ti P/ws fl/MW Dec. 6, 1938. i H. EQPRUSS 2,139,625

' PLOW Filed Nov. 2. 1936 3 Sheets-Sheet 2 Hugo L. Pram INVENTOR.

ATTORNEY.

Dec. 6, 1938. H E, R'US 2,139,625

now

3 Sheets-Sheet 3 FIG. /0

Hugo P/UJJ' INVENTOR.

QM WW ATTORNEY.

Patented Dec. 6, 1938 UNITED; sraeras- O F F LCE PLOW ApplicationNovember-2,- 1936,: Serial :No: 108,769:

141 Claims;

This invention relates to plows- -whiclrareiat'-'-- tached to anddrivenby ai vehicle; especially to road plows-, such snow plows,butfim'ay beapplied to ice, dirt or other similar ploWsL More t.specifically," the present invention is concerned with an improvement inthe attachmentfor secur--- ing 'tliei plow' and-its supporting: frame toair-vehicle', such as a motor tmck or tractor.'- It is particularlyapplicable to-plows whi'ch-are' detachqv 'ably secured to motorvehicles; but' isalso appli cable to permanent installations.

It is known to attach a plow frame to a vehicle:

by means of a-pivot fixed to 'a part; of tlie vehicle, such as a truckaxle, whereby the plow -can 'be 51i'swungupwardly to adjust the height;of the plow blade in relation'to' the ground, and-the 'depthto which the'cuttingedge enters the -'snow or soil may thereby be controlled and theplow placed intoand out et operation; Such: a 'constmeti'on olds, forexample, described in the United State's patent'to Hewitt'No.2,0555'794) In suchade'vice the weight ofthe plow share orblade,--as'well as of the forward-endof the-frame, is carried-by running devices,such as one or more wheels aorgqsleds, attached to the forward end ofthe- -fram'e and the frame functions mainly' to='transmitahorizontalforce to 1 pushthe plow into -'the ma-- terial-to beexcavated, and to steer it-inthe-de si-reddirection. Whileiit' iscustomary to mount m theblade in front of the vehicle, it may also-bemounted in rear of it,

The horizontal thrust carried by the frame insuch constructions isconsiderable; and it: has

been necessary to provide a pivot bearing and. a.

;;frame structure of generous dimensions to insure the life of thebearing-and to prevent bucklingof the frame.

Insuch. a construction, moreover, the frame-is rigidly pivoted to thevehicle-so that whenever u-the vehicle is tilted laterally theplow-issimilarly tilted. This may occur, for example, when one tire islarger than the other tire on'the same-axle,

or when one wheel passes over'an obstruction, or enters a depression,or, when clearing snow or. other material from a-roadway','when one sideofthe truck is off of the pavement.

The tilting of the plow frame prevents the plow fromdigging.

the:groundri. These difiicultieszare; encountered in plows."whichrarevmounted; perpendicularto the longitudinalaids ofithezvehicleaswell 'asin plows. which are mounted diagonallywithrespect to; thesaidaxisaa This'zdifficulty'has rin.the:past, -made,-1t.imprac-. tical'to mount the plow'frame to'asprung chassis,-. which isoften subject totilting .withrespect to the: ground; duetoswaying 501' unequal loading,neces-\- sitatingqtheufasteningz of-the pivot and frame to the axle: ofthe :vehicler. Such' a: mountingis, however,.undesirable becauseritplaces an undue stressmpon-:theztruokraxle-andlthebracing-structurewhich holds ':the-.:axle in. alignment. to the truck, and-becauseinsuficient space is. available near-theaide for. providing pivots and.frame membersaof the necessary strength;

As. further difliculty. encountered in: such. constructions;andaparticularly in? connection with; plow blades which,zlike that'shownin-lthe-I-Iewitt patent, above =referred-.to;. are disposed. diagonallywith'respect to theraxisof the-vehicle and the. axis of Ithepivotsfimthat .whens-the height ofthe plow is=adiusted.with.respect:to the g-round; or snow surface, both ends of the plow blade cannot be25.:

made to rise the "same. distance. This is due to the-fact that both;ends. of the blade are. pivoted about the same'pivot a-xis sothat the.end of the plow-the farthestzremoved fromthevehicle, due to its longerradius',.'swings through a greater. vertical distance than the otherendof the blade. It, for example, the: rearward runner of such apush'plowemployed to-remove: snow passes over atmoundofsnowandisltherebylifted, the leading runner, instead of remaining-on.the surface, will be lifted through a vertical distance which is greaterthan the: lift on the rearward runner, placing; aftorsional stress on:the frame and preventing effective removal ofpsnow from; the areatraversed by the leadingend-of the blade. Simi- Ian difficultyiszencounteredwhen the blade is intentionally raised orlowered.

Still. another difficulty encountered in plows. which are diagonallymounted with respect tothe vehicle and frameis that the forward end of45, the frame canbe maintained in its proper vertical position. with.respect to the ground or .snow only when thelpivot axison-the truck isat the correct height above-the ground.- When the-tires on the truck-arechanged, or .when. thetruck-moves over rough ground, the axle orchassis. frame is .higher or lower. than.- the height for; which theframe was designed, and thedifficulties describedin the precedingparagraph are also encountered. This circumstance, moreover, makes itimpossible to attach the plow frame to a vehicle other than the one forwhich it was constructed. Broadly, the present invention contemplatesthe provision of a novel and improved plow frame particularly adapted tobe attached to a vehicle which is capable of moving the plow forwardlyand maintaining it in its proper direction of travel, while permittingthe plow to assume its proper positioning with respect to .the ground orsnow surface irrespective of the height or lateral.

inclination of the vehicle or the relative vertical position of thesupporting runners.

It is an object of the invention to provide an improved means forattaching a plow frame to a vehicle which may be attached toa. sprungportion, as well as to an unsprung portion of the vehicle, and whichwill permit the vehicle to 'move over rough and irregular ground. It isa further object to provide a novel and improved attaching means whichwill permit the plow to be attached to vehicles of different heightsabove the ground, and to operate efiiciently regardless of variations inthe height of the vehicle axle or chassis with respect to the ground.

A further object of this invention is the provision of a means forattaching the plow frame to a vehicle in a manner which will permit theend of the frame nearest the vehicle (either forwardly or rearwardly) tohave a constrained vertical movement with respect to the vehicle. Afurther object is to provide a. plow frame which is better able totransmit horizontal thrust to the vehicle and have a lesser tendency tobuckle than the frames heretofore employed.

Still another object of the invention is the provision of a plow framehaving a diagonally disposed plow blade which-may assume its properposition with respect to-the ground or surface of the snow, irrespectiveof the lateral inclination of the portion of the vehicle to which theframe is secured. A further object is to provide a plow frame which maybe attached to a vehicle so as to have free lateral tilting and verticalas well as vertical'tilting movements with respect to the vehicle.

The above and additional objects, which will hereinafter be morespecifically treated, are attained by such means as are shown in theac-' companying drawings, described in the following specification, andmore clearly pointed out in the claims. While I have in the followingspecification described only four specific embodiments of the invention,and have described these with sufiicient detail to enable those skilledin the art to which it pertains to understand the mode of constructionand the principles involved, it is to be understood that there is nointentional limitation to the specific forms and precise details shown,and that various modifications of the same can be resorted to withoutdeparting from the spirit and scope of the invention, and withoutsacrificing the benefits derivable therefrom. It is also to beunderstood that certain features of the invention herein disclosed maybe employed in and with other combinations than those shown anddescribed.

The invention will be described as applied to a snow plow of the generaltype shown in the Hewitt patent, above referred to, it being understoodthat it may be employed in connection with the rotor shown therein, orwithout it, and that persons skilled in the art of excavating can makesuch modifications as are necessary to adapt the invention to otherpurposes. In the drawings:

Figure 1 is a fragmental side elevation of a snow plow comprehending thepresent invention, as it would appear when operatively connected to itscorrelated automotive vehicle, the plow blade being shown partly insection.

Figure 2 is a top plan view thereof.

Figure 3 is a horizontal section taken on line 3-3 of Figure 1,illustrating the mounting of the frame to the transverse girder orbolster. Figure 4 is a transverse section taken on line 4-4 of Figure 3in the direction of the arrows.

Figure 5 is an elevation view of a pump employed to operate the liftingram.

Figure 6 is an enlarged fragmentary perspective view illustrating thepreferred mode of supporting the transverse bars and girder on the sideabutment plates which ar e attached to the vehicle.

Figure 7 is a transverse section taken on line 1-! of Figure 2,illustrating the mounting of g the transverse girder.

Figure 8 is a fragmentary side elevation of a modification of a portionof the frame and attaching means.

Figure 9 is a horizontal section taken on line 9--9 of Figure 8.

Figure 10 is a fragmental horizontal sectional view,-partly inelevation, similar to Figure 3. showing a further modification of myinvention.

Figure 11 is a transverse section taken on line ll-ll of Figure 10 inthe direction of the arrows.

Figure 12 is a horizontal vertical view taken on line |2l2 of Figure 10.

Figure 13 is a fragmental horizontal sectional view, partly inelevation, similar to Figure 3, showing still another modification of myinvention.

Figure 14 is an end view of the construction shown-in Figure 13.

Referring to the drawings, and particularly to Figures 1 to 7 thereof,Iil is the sprung chassis of an automobile or similar vehicle, which maybe provided with springs, not shown, and having an engine compartment Hand wheels [2. A pair of abutment plates I 3-l3' is secured to thechassis by detachable bolts, as shown. The abutment plates are spacedapart and rigidly connected by a pair of transverse channel bars l4-|4',with vertical webs, and a third channel bar l5, welded or otherwisesecured to the inner faces of the plates I3-I3'. The bars 14-44" areprovided with a removable pin or bolt l6. braced by a bushing 11, andforming a trunnion rotatably supporting a tiltable bolster 18, locatedbetween the bars l4, and extending through notches [3a, cut in theplates I 3-[3 (see Figures 6 and 7). The notches have verticaldimensions to permit the bolster I3 to tilt in a vertical plane aboutthe pin l6 through an arc of about 10 to 15 degrees on either side ofhorizontal. The vertical faces of the notches are smooth, and arepreferably provided with bearing surfaces by welding face plates I 9-l9' thereto (see Figures 3, 6, and 7). The plates l9-I9 are located toengage the forward and rear edges of the bolster I8, so as to preventits rotation about a vertical axis, thereby forming abutment means totransmit longitudinal stress from the chassis I0 to the bolster.

A rigid tower 20 is mounted on the abutment plates' l3l3, braced by tierods 2|-2I, and provided with resilient supporting means and hoistingmeans, hereafter described.

The details on each end of the bolster I 8 are videia 'vertial'. grooveon its outer face; A 'verendof, the} ter'fltliis' 'apai'rIofforwardly'ex;

bers'sof the plowsupporti'ng fram'L' A plurality l"of ,holes'.21is'providedinithe' bars for receivingan adjustable 'pi ri 128';adaptedto, rest on the upper edge of the plate .2 4,t01i1nit the,downward movementjoff the ba'r125 in' its groove.- A

.. ,se 'c oiid' pin'129 may, if desired, be similarly infzdser tedinahole below the plate 24 to limit the upward travel. If desired, thepin's"28 arid,,23 may be located so as' entirely to'p'revent a slid ingmotion, v A struts 26 may be suitably reinforced "aga inst buckling,an dprovided with a transverse bar30, The forwardends' of the struts arecurved to fit the rear surface 'of' a plow blade 3|, ,to which they maybe fi$edly1secured,'as' shown,

but towhi ch theymay be attachedin the manher illustrated in Figureslfto" 3 jand 7, of the. Hewittpatent, referredtd above. I The weightThe. midway point'b'etweenftlie ribs 31' s1 is generally ofi-center, andlocate'd'so'as tobalarice ,gtheweight of the frame and plow when thesame are swung upwardly about the journals 22 to place'the plow. out ofoperation, or, during, operation, to elevate the blade to clear anobstruction' or to make a shallower cut into the snow. 6 The ram 36 maybe operated by a hand or motor driven pump 38, preferably operable orcontrollable from the driver's compartment of the truck, andlconnectedto the ram by means of fluid pressure transmitting tubing 39. The ramand g 'its attaching means are so constructed as to permit the frame tobe tilted upwardly through an angle of about 30 degrees abovehorizontal. While the ram may be employed to raise the .blade duringoperation .asstated above, it nor- 0 m'aIly, supports no weight when theplow is resting. on' the runners. 32 -32'.

According to the novel means for supporting the plow and its framelwhenin operation conternplat edir'i one embodiment of the presentins'vsno'omme, weight of these parts is carried by three points: The tworunners 32. and 32' support thewei'ght of the front portion of thestructure; the rear portion, of the frame is supported from the tower20, by acable 40' which is pref- 7 erabl'y providedwith a turnbuckle" 4|and a coiled spring42. r.,s1mnar, resilient means for restraininglyslpportin'gfthe rear end of the frame; but the resilient s'pringmay, ifdesired, be omitted. .Th po nrorattachment ofthe cable 40 is gen- 75erally ofi-cntiffand is'preferably so chosen,

arse-see af'circular' disc. or jourrial" 22, revolvably' w IThe'bearing" 5 member'23'iis"fiiedfto'ja plate 24, haped to pro;

edly' saatsafmss has 2% its on j each" A hydraulic or oil ramis'suspended from and thelefi th I th thesprin'gfarejsueh, 'th theweight of the rear enjd" offthejlfra'mej, is"b a1'a d' with respect tothe" runners 324-321.; Infith'is manner no weight is,fduring"jt henormaljoperation',"carried by the 5 pins; 28' ad"29,',"these"plnsjserving merely as safety gleyic'es 130, h'olthe1resi1ient g I v hasajrestrained yertieaim'overi ent with respecttof'the 'truckf aiidflexibllityland j stability are insuredfv fljhe'three: polnt' support, moreover, (whether'brintfth'e' cage is providedwith a 15 resilient means); make'sjit possible for both ofthe"runners""32 32 to'"be 1n"conta ct with the ground pr snqw surface,regardless fof the relative eievandrisiqi' he., i1r; s e suppor n thesenner's, and"irrespctiveof the lateral tilting of the 20" truck. We

If, fo r e rampl; 'thxi truclris tilted laterally with respect'lto'the""runners"or the frame, the framefis'free'to tuijnabdQtQajstibStantially longitudinal'axjsjjbing supporte'd onlyby thecable 25- 491 The struts" 28, jbeing"a1 part of' the frame, will in t isCase transmit the transverse turning motion tothefbolster"l.8lbyfmearis'of the bearings' 23 'and j ournalsj2 2f; ,butjthis' ibolster isfree to pivot about'tlie; n "pinltiand'torsional stresses in the fr 7,

re taurant; no ,;,t lthefl cablejll is not ndisp ns bl j nestmiqh 'asfhe we t o the rear endof the'fraine'c ri'alsofbe supported by the ram'36, which may b attached to the frame at ajpoint toadapt'itito'perform'both the function'of lifting'the fram'e aboutthe'journals 22 when it is desiredto swing; the blade'iil upwardly,ancllthetunctiqn abdve described for the cable 5p; Einally;itflis" alsopossible to dispense entirely with a pen'dant suspension means for the'rear end of the'frame durin fihe normal operation (therebyeliminatiriglthe cable All and either eliminating also the rarh36 andtower 20, or employingthelatter only for swinging the frame upwardly)and toca'rry the weight of the rear end of the frame by means of thepins 28, journals 22, and the trunnion pin 16, in which case the pin l6will functio n as the third point of support and'a three point ofsuspension will 0*" be realized.

It should also be noted that the relative vertical slidinginotion'between the bar 25 and the plate 24 improves the flexibility of thedevice,

particularly when e cab e! is employed, since it prevents thetr'ansmission' of a substantial amount of vertical thrust from the frameto the bolster 18' and' the' mdfiQ f vehicle, This relative slidingmovement" is also of advantage whether or not thecable 40 is employed,since it permits 66" the abutment plates 3 -Ql '3' t be attached tomotor vehicles of difiernt heights without requiri'ng a reconstructionof the frame and struts 26, the pins 28 and 29 being merely insertedinto the proper holes, ever, not'jndispens'ableto the operativeness ofthe device, inasmuch as it' is possible to carry the weight of the rearend] of the frame by the trunnion pin l6, as pointed; out above, and yetprevent torsional stresses in the frame. In this 78 case the struts2$"xnay be' fixedly attached to the plates 24 or the pins28 and 29 maybe adjusted to prevent a relative vertical sliding movement betweenthese parts. V

During the operation-6r the plow the horizontal 76 The sliding motionis, howstress is completely transmitted from the frame by its struts 26to the bolster l8 and from the bolster [8 to the abutment plates |3l3 bythe abutment of the front and rear edges of the bolster on the verticalfaces of the notches I 311 in the plates Iii-I3. This arrangement at thesame time maintains the frame in the proper directional alignment withrespect to the vehicle. Since the vertical edges of the notches in theplates |3-|3' carry considerable stress it is desirable to reinforcethese plates and, moreover, to increase the rubbing surface beyond thethickness of the plates. This may be effected either by mounting thebars I 4-H so close together that the bolster bears against their innerfaces, or by attaching the smooth face plates l9--|9' on the verticaledges of the notches l3a, as described above.

When it is desired to detach the plow and frame from the vehicle it isonly necessary to pull out the pins I6 and 29 and to disconnect thecable connections depending from the tower 20.

The bolster 18, together with the journals 22, bearings 23, and plates24, may then be slid downwardly and out of engagements with the plates|3-|3 and the bars 25. Alternatively, the pins 16 may be left inposition and only the pins 29 removed, the struts 26 and the bars 25being then lifted out of engagement with the plates 24. The plates [3-[3may then be readily unbolted from the truck chassis. It will be notedthat the frame is very rapidly and easily attached to and removed fromthe vehicle. If desired, the plates l3-l3' may be left on the vehicleduring the winter season, thereby still simplifying the operation ofplacing the plow into operative order. Moreover, the plates |3-l3 andits tower may be employed with a dirt plow in certain seasons, and witha snow plow in other seasons.

In the slightly modified form of the attaching means shown in Figures 8and 9 the struts 26 are further braced against buckling and the stresson the journal is reduced materially. In these figures partscorresponding to those described above in connection with Figures 1 to'l are indicated by like reference numerals. The abutment plate l3, itsface plates I9-l9, the bolster 18, the plow frame and its supportingrunners and cables are each similar to those of Figures 1 to 7. Avertically elongated bar 44 is fixedly attached to each end of thebolster I6, and is provided with a plurality of holes 45. A slide 46having inwardly projecting guides 4l4l' and flanges, as shown, isarranged to have a vertical sliding motion with respect to the bar 54.The vertical dimension of the slide 46 is less than that of the bar 44,and the vertical movement of the slide 46 may be limited or prevented bymeans of pins 48 and 49 which may be inserted into the holes 45.

The outer face of the slide 46 is provided with a journal or pin 50,passing through a horizontally elongated hole or slot 5| in the thrustmember 52. The member 52 is fixedly attached to the strut 26 or may beformed integrally therewith. The plate 26 is attached to the plow bladeat its forward end as shown in Figures 1 and 2. The inner face of themember 52 is provided with an arcuate flange 53 having its center ofcurvature at the center of the journal 56. A coacting arcuate flange 54is formed on the slide 46 and is shaped to fit the inner face of theflange 53. The slide 46, together with the flange 53, constitute asecond thrust member.

Since the slot 5|. extends longitudinally with respect to the member 52,it will maintain the member 52 in its proper vertical position withrelation to the slide 46; but horizontal thrust is carried entirely bythe contacting faces of the flanges 53 and 54. As a result of theseflanges the stress on the journal is greatly reduced, and the length ofthe member 52 through which the horizontal stress is carried isshortened, thereby reducing the tendency to buckle. Moreover, the flange53 has an appreciable vertical dimension and the member 52 can,therefore, be more easily reinforced to transmit horizontal force.

The modes of operation of the embodiment illustrated in Figures 8 and 9are similar to those described above in connection with Figures 1 to 7.It should, however, be noted that the coacting arcuate flanges may alsobe employed in connection with other forms of plows which do notcomprise the tiltable bolster and/or the vertical slide. Thus, thethrust member 46 carrying the journal 56 and the flange 54 may beattached directly to the chassis of a vehicle.

In the modification illustrated in Figures l0, l1, and 12, the bearingsand journals 22 and 23 are eliminated by employing a circular transversebolster 55 rotatably mounted in slides 56-56. The slides 56-56' aremounted to engage the vertical edges of a notch 51a formed in abutmentplates 5'l-5l', which are similar to the abutment plates l3l3' shown inFigures 1 to 7, and which may be similarly attached to the chassis ofthe vehicle and similarly braced by channel bars 58 -58.

The bolster 55 may be retained by means of a pin or trunnion bolt 59extending between the bars 58-58' and through an elongated hole 66 inthe bolster 55, the hole being shaped to permit the bolster to rotateabout its axis through an arc of about 30 degrees or less. The bolsteris laterally tiltable about the pin 59 through an arc of about 10 to 15degrees on either side of hori zontal. The slides 5656 are therebyprevented from moving out of the notches.

The slides 56-56' are provided on their front and rear faces with a pairof grooves Gl-Bl to receive the walls of abutment plates 5l5l. Thebottoms of the grooves are plane surfaces spaced so as to engage thevertical edges of the notch 51a (see Figure 11); the side faces of thegrooves are curved, as shown in Figure 12, to engage the side walls ofthe plates 5l-5'." when the bolster is tilted laterally about the pin59.

A vertically elongated bar 62 is fixedly attached to each end of thebolster 55, and provided with a plurality of holes (not shown, butsimilar to the holes 45 in the bar 44 shown in Figure 8). A slide 63,having inwardly projecting guides 64- 64 and flanges, as shown, isarranged to have a vertical sliding motion with respect to the bar 62.The vertical dimension of the slide 63 is less than that of the bar 62,and the vertical movement of the slide 63 may be limited or prevented bymeans of pins 15, as described above in connection with Figures 8 and 9.Struts 55-65 (corresponding to the struts 26-26 shown in Figures 1 to'7) are fixedly secured to the slides 63, and form the sides of the plowframe.

The modes of operation of the embodiment illustrated in Figures 10, 11,and 12 are similar to those described in connection with Figures 1 to 7.When the plow frame is swung unwardly to clear an obstruction or toplace the plow out of operation the bolster 55 rotates in the slides 5656 and about the pin 59. Otherwise the function of the device isidentical, i. a, it may be supported mythepable kfl, or -the weight ofthe rear portion fiftheframe may'-be:carried by the trunnion pin W59.

Ih the embodiment shown Figures 10, 11, and I2 'the =downwardmovement'of the'slides' 56--56' -may 'be limited by stirrups "ll attached 'to the=plates 5 l- 51' asshown, andthe en'dwisemove- -mentof the bolster inthe slides may be limited Jbymeans of *pinsGB-JSB. (A limited endwisem0tion-is necessary.) When these added features are provided, thetrunnionp'in 59 may in certain cases be omitted.

Accordingto the fourth modification, shown in Figures 13 and 14, abolster in the form of'a continuous transverse girder may be omitted. Inthesefigures, abutmentplates-fi'l- -tl', carried by the chassis of 'thevehicle, are provided with 'slides 68*68-and with stirrups- 69 to limitthe downwardmovement of the slides,-all as shown in Figures 1-0, 11, and12. Rotatably mounted in -each sli-de 68'is-a'heavybolster pin 10,provided wir'ith a' nut 72 to have a limited endwise motion. struts' l-3'l3', forming the side plates of the plow frame, and -.corresponding tothe struts 26* '16" of Figures" I to 7 are fixedly secured to the pins10 in-"this modification, :the frame may be -swung upwardly by' rotationof the pins"!!! in the slides -6868. These slides may float betweentheir =u-pperandlower-positions when the rear end pf theframe--is--supported -'by the cable 40; when *this 'is not employed,they-may rest on the stirrups 69,'=which=may be provided with anadjustablebolt H' 'to Jimit the downward movement.

When the plow frame is tilted laterally one slide movesverticrlly-withrespect to the other, :thereby preventing torsionalstress in the frame, andzmaintainingithe plow blade in its properposition with'respect to the ground.

.Inciaim as my invention:

1. The combination with an automotive vehicle of a transverse bolsterattached to said vehicle rotatable in a substantially vertical planetransverse to the vehicle and secured to transmit longitudinal thrust tosaid vehicle, a plow frame extending longitudinally from one end of saidvehicle having a plow attached thereto at one end thereof, slide meansinterposed between the other end of the frame and said bolster arrangedto permit said other end of the frame to be adjusted vertically withrespect to said bolster, means to lock said slide means in an adjustedposition, said bolster being arranged and constructed to permit saidframe to be swung upwardly about a horizontal transverse axis at thesecond end of the frame.

2. The combination according to claim 1 in which the bolster issupported at a point intermediate its ends by a trunnion pin disposedlongitudinally with respect to said vehicle.

3. The combination according to claim 1 in which the said second end ofthe frame is nonpivotally attached to the bolster by the said slidemeans, and the bolster is rotatable about its own axis.

frame extending longitudinally from one end of said vehicle hav-ing a'plow-"attached thereto at cone end thereof, and a pair of strutsextending to the other endpslide means interposed between said strutsand 'said bolster arranged to permit :said struts-to be moved verticallywith 'respect to said bolster, said slide means=comprising two-juxtaposedvertically extending members,- a pmralitysof-rperforations inat least ai first of said members, and P removable pin means extendingthrough sa'id perforated-first member engageable with "the second memberto limit'the vertical movement between said "members, whereby theheight' of said struts with respect to the'bolster 'rnaybe a'djusted.

*6. A plowcomprising-a pair of laterally spaced :abutment plates and :anintermediate longitudi- '-nally' disposedtnunnion'adapted tube-attachedFtOlWlIIlOtOIWGhiGlE, .a' transverse bolster rotatable m'boutuits 'zownraxis sand -pivoted about the trunniomaxis, and z'anplow'framemounted-upon said ibolstenf-each of: said-abutment platesbeing-providedwitha substantially vertical face-near said :bolster andin thrust transmitting relationship thereto, whereby longitudinal thrustfromsaid :plow .frame maybe transmitted through .said :bolster:tossaidrabutment .plates.

7. :Aplowrcomprisingraipair of laterally spaced tabutment plates: andanintermediate longitudinally disposed-trunnion pin-adapted tube attachedto=a .motor vehicle, a transverse bolster, a longitudinal, werticallyelongated .-hole in said .bolster said trunnion pin passing through saidhole, whereby .-said bolsterv is supported and .is trotatable about-its'own taxis; and pivoted about the axis of the trunnion pin, each of saidabutment plates .being provided with :a substantially vertical:faceznear @said bolster .and .in thrust transmitting .-.relationshipthereto, whereby longitudinal-thrustfrom said :plow framemay betransmitted .-.through.'.-said bolster to said abutment plates.

8. A plow comprising a pair of laterally spaced abutment plates and anintermedite longitudinally disposed trunnion adapted to be attached to amotor vehicle, a transverse bolster rotatable about its own axis andpivoted about the trunnion axis, a plow frame mounted upon said bolster,each of said abutment plates being provided with a substantiallyvertical face, and a slide near each end of said bolster revolvablyhousing the same and in sliding engagement with faces in said abutmentplates, whereby longitudinal thrust from said plow frame may betransmitted through said bolster and slides to said abutment plates.

9. The combination with an automotive vehicle of a pair of spaced platesattached to the frame of said vehicle, said plates having verticallydisposed notches, a bolster extending transversely with respect to saidvehicle and through said notches, mounted to be rotatable about thelongitudinal axis of said vehicle and to slidably engage the verticaledges of said notches, a plow frame having a pair of side members, pivotmeans for connecting one of said side members to each end of saidbolster, whereby said frame may be swung about the axis of said bolster,and a plow blade attached to the end of said frame remote from saidbolster.

10. The combination with an automotive vehicle of a pair of spacedplates attached to the frame of said vehicle, said plates havingsubstantially vertically disposed edges, a vertically movable slide oneach of said side plates engaging said edges, a bolster extendingtransversely with respect to said vehicle rotatably mounted in saidslides, a plow frame having a pair of side members, means for attachingone of said side members to each end of said bolster, and a plow bladeattached to the end of said frame remote from said bolster.

11. The combination with an automotive vehicle of a pair of spacedabutment plates attached to the frame of said vehicle, said plateshaving substantially vertically disposed edges, a bolster extendingtransversely with respect to said vehicle mounted to be rotatable in asubstantially vertical plane transverse to said vehicle and to transmitlongitudinal thrust to the vertical edges'of said abutment plates, aplow frame having afirst thrust member extending forwardly from saidvehicle on each side of the frame, a plow blade attached to the forwardend of said frame, and means at each end of said bolster for rotatablyconnecting the rear end of said frame about a pivot axis substantiallyparallel with the axis of the said bolster comprising a second thrustmember carried by said bolster and extending forwardly from said pivotaxis, a pin substantially at said pivot axis carried by one of saidmembers and extending through a longitudinally elongated slot in theother of said members, a first arcuate flange carried by said firstthrust member having its center of curvature at said pivot axis, and asecond arcuate flange on said second thrust member in engagement withsaid first flange, disposed so as to transmit longitudinal force fromsaid plow frame to said second thrust member between said flanges.

12. The combination with an automotive vehicle 01' a plow frame having afirst thrust member and extending forwardly from said vehicle, a plowblade attached to the forward end of said frame, and means for rotatablyconnecting the rear end of said frame to the vehicle about a pivotcenter comprising a second thrust member carried by said vehicle andextending forwardly from said pivot center, a pin substantially at saidpivot center carried by one of said members and extending through alongitudinally elongated slot in the other of said members, a firstarcuate flange carried by said first thrust member having its center ofcurvature at said pivot center, and a second arcuate flange on saidsecond thrust member, in engagement 'with said first flange, disposed soas to transmit longitudinal force from said plow frame to said secondthrust member between said flanges.

13. The combination with an automotive vehicle of a plow frame movablyattached to one end of said vehicle and extending forwardly therefrom,thrust transmitting means for transmitting longitudinal force from theframe to said vehicle, a plow blade mounted at the forward end of saidframe diagonally with respect to the axis of said vehicle, a pluralityof spaced runners near the forward end of said frame for supporting theplow with respect to the ground, and supporting means attached to thevehicle forming a single point vertical support for the rear end of saidframe comprising a bolster fixed to the rear end of the frame anddisposed transversely with respect to said vehicle, a longitudinal,vertically elongated hole at an intermediate point in said bolster, anda longitudinally disposed trunnion pin carried by said vehicle passingthrough said hole, whereby said bolster is supported by said trunnionpin and may rotate about the trunnion axis and about its own axis.

14. The combination according to claim 13 in which the bolster isadjustably secured to said frame by means permitting vertical adjustmentbetween the bolster and the frame.

HUGO E. PRUSS.

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